| Autor: |
Calandri, Enrico, Giraudo, Maria Teresa, Sirovich, Roberta, Ostan, Antonella, Pultrone, Mirco, Frantellizzi, Viviana, Conversano, Lucia, Bagnasacco, Paolo, Gallina, Sonya, De Vincentis, Giuseppe |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Current radiopharmaceuticals. 15(3) |
| ISSN: |
1874-4729 |
| Popis: |
Background: An accurate measurement of the target volume is of primary importance in theragnostics of hyperthyroidism. Objective: Our purpose was to evaluate the accuracy of a threshold-based isocontour extraction procedure for thyroid tissue volumetry from SPECT-CT. Methods: Cylindrical vials with a fixed volume of 99mTcO4 at different activities were inserted into a neck phantom in two different thickness settings. Images were acquired by orienting the phantom in different positions, i.e., 40 planar images and 40 SPECT-CT. The fixed values of the isocontouring threshold for SPECT and SPECT-CT were calculated by means of linear and spline regression models. Mean, Median, Standard Deviation, Standard Error, Mean Absolute Percentage Error and Root Mean-Square Error were computed. Any difference between the planar method, SPECT and SPECT-CT and the effective volume was evaluated by means of ANOVA and posthoc tests. Moreover, planar and SPECT-CT acquisitions were performed in 8 patients with hyperthyroidism, considering relevant percentage differences greater than > 20% from the CT gold standard. Results: Concerning phantom studies, the planar method shows higher values of each parameter than the other two methods. SPECT-CT shows lower variability. However, no significant differences were observed between SPECT and SPECT-CT measurements. In patients, relevant differences were found in 7 out of 9 lesions with the planar method, in 6 lesions with SPECT, but in only one with SPECT-CT. Conclution: Our study confirms the superiority of SPECT in volume measurement if compared with the planar method. A more accurate measurement can be obtained from SPECT-CT. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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